Can people compare stimulus information by a ratio operation?

by Clairice T. Veit

Purchase Print Copy

 FormatList Price Price
Add to Cart Paperback23 pages $20.00 $16.00 20% Web Discount

The debate about people's ability to estimate ratios or intervals has raged for decades. This paper describes research that produced the debate, experimental paradigms and research that resolved the debate, and the pitfalls of deriving scales from and basing conclusions on incorrect comparison operations. Historically, researchers believed that respondents followed task instructions when asked to judge ratios or intervals and that resulting numbers represented the scale of sensation for the stimulus dimension. However, nonlinear, nearly exponential relationships consistently resulted from ratio and interval judgments of the same stimuli. This empirical contradiction threatened to defeat the goal of developing single scales of sensation for stimulus dimensions. Recent research employed factorial designs that allow tests of hypothesized comparison models and distinction between subjective and response values. The evidence suggests that people's underlying operation is subtraction when performing both ratios and intervals of two stimuli. Research supports the conclusion that people can compare stimulus information by a ratio operation only when the stimulus information is in the form of differences or distances.

This report is part of the RAND Corporation paper series. The paper was a product of the RAND Corporation from 1948 to 2003 that captured speeches, memorials, and derivative research, usually prepared on authors' own time and meant to be the scholarly or scientific contribution of individual authors to their professional fields. Papers were less formal than reports and did not require rigorous peer review.

The RAND Corporation is a nonprofit institution that helps improve policy and decisionmaking through research and analysis. RAND's publications do not necessarily reflect the opinions of its research clients and sponsors.